Fuel Injection Angle Research Articles

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

On the impact of fuel injection angle in Euler-Lagrange Large Eddy Simulations of swirling spray flames exhibiting thermoacoustic instabilities

Piston Crown Profile Modifications for Various Combustion Mode Strategies of Modified GDI Engine towards NOx and PM Reduction

In the current development of automotive engines, the major target is to design a combustion chamber in such a way that the combustion process must provide very less concentrations of emissions. To satisfy current worldwide emission norms, petrol engines also equipped with direct fuel in-jection (gasoline/petrol directly injected into engine cylinder) same as like diesel engines. The main drawback of GDI engine is NOx and PM emissions due to lean burn combustion and rich mixture formation over the combustion chamber surface because of wall wetting. In GDI engines, the gasoline fuel injector is placed at various positions with different angles over an engine cylinder head as per the mode of combustion strategy. Based on the mode of combustion with fuel injection angle, the piston crown shape design in much important that the crown surface must not involved in wall wetting during injection. The piston crown shapes were modified for Spray guided combustion mode, Wall guided combustion mode and Air guided combustion mode by keeping in mind that the position of injector with fuel spray angle and the position of spark plug tip on the cylinder head. The main aim of modifying the crown surface profiles of piston is to impart swirl and squish effects for better mixing of air and injected fuel, maintain combustion chamber surface temperature range within the limits and also to avoid wall wetting results in chances of reducing soot particle/PM emission and NOx emission from combustion process.

Computational studies of fuel injection strategies on natural gas combustion characteristics in direct-injection engines

This paper studies the influences of different fuel injection strategies on flame propagation and combustion characteristics in a glow plug assisted direct-injection natural gas engine. Our previously existing version of the KIVA-3V CFD code incorporates a model of internal flows in the gaseous fuel injector and also a detailed model of the glow plug and its shield. This study was conducted by using the KIVA-3V code with added improved emissions models, including a detailed kinetic chemical model and a modified phenomenological soot model. In the simulation, a low temperature natural gas mechanism is selected to estimate the gaseous species, and acetylene was chosen as the key species to model the soot formation. The simulation indicated that the fuel injection duration, injector nozzle size and injection angle can affect the natural gas combustion characteristics. Generally, shorter injection duration reduces both peak cylinder pressure and emissions in the natural gas engine; however, the natural gas flame propagation cannot be maintained once the injected fuel mass is lower than a limit. The simulation also reveals that the injector nozzle size highly affects the natural gas combustion by inducing diffusion combustion for a small diameter nozzle and partially premixed combustion for a large diameter nozzle. Compared to a large nozzle, a small nozzle results in a faster pressure rise with more engine emissions and lower combustion efficiency. The fuel injection angle can influence natural gas combustion characteristics by affecting the flame propagation out of the glow plug shield in the initial combustion stage.

Integrated control of torque and emission of a diesel engine based on LPV‐MPC

This study presents an integrated control scheme of a diesel engine which aims to ensure quick torque response while limiting the average NOx emission below the certain specification. To start with, the sensitivity analysis is performed to recognize the key factors determined to balance emission, torque and fuel consumption. Considering the strong nonlinearity of the diesel engine, a multi-input multi-output (MIMO) linear parameter varying (LPV) model is developed. Unlike the conventional state-depended LPV modelling process, the proposed LPV model is built based on a kernel function with a novel form of state-free predictive equation so that the system outputs are directly computed. The control objective of coordinating torque tracking and emission reduction is then accomplished by designing a model predictive controller that regulates the fuel injection quantity, fuel injection angle, exhaust gas recirculation (EGR) rate and the opening degree of variable geometry turbine (VGT) valve. Finally, the developed LPV model and the MPC controller are testified with a high-fidelity commercial diesel engine model. The results show that the LPV-MPC controller is able to satisfy the NOx emission specification and the engine torque tracks the desired reference fast in transients, while the control variables are suitably actuated within the actuator constraints.

Effects of fuel injection angle on mixing performance of scramjet pylon-cavity flameholder

A numerical investigation on the effects of fuel injection angle on various mixing parameters within a pylon-cavity aided supersonic combustor flameholder under non-reactive flow conditions is performed. The computational model based on Reynolds-averaged Navier–Stokes equations for compressed real gas is solved by a coupled, implicit, second-order upwind solver with a two-equation Menter’s shear stress transport turbulence model. The steady simulations are experimentally validated using wall pressure data, two-dimensional (2D) velocity field, and fuel mass fraction. Three distinct fuel injection locations at the cavity floor are used for sonic hydrogen fuel injection at 90° and 45° injection angles, with a crossflow Mach number of 2.2. The results show deeper fuel jet penetration capability for the transverse injection when compared to an angled injection, whereas better mixing capability is observed for the latter. The fuel jet vortex pairs formed due to the interaction of the surrounding cavity flow with the barrel shock play a vital role in the mixing mechanisms. The lower pressure regions due to the barrel shock result in the formation of a secondary fuel jet vortex pair. The Kelvin–Helmholtz instability observed between the counter-rotating vortex pairs results in the formation of smaller eddies, which enhance the fuel dispersion and transport.

Methyl hydroxide combustion in a diesel cylinder and its effect on the cluster of carbon black

In studies of carbon black education on a model setting during the injection of secondary liquid fuel into the combustion products, the existence of an poise operation temperature, i.e., the temperature at which the operation is characterized by poise between the combustion and decay rates of the fuel in thermal terms has been established. The cluster of smokiness education varies depending on changes in the setting fuel injection angle of a CI engine. At the same time, it is possible to determine with certainty the optimal fuel supply angles in the diesel cylinder both when working on diesel oil, and when working on methyl hydroxide with a pilot portion of hydrocarbon fuel.

Heat release indicators when working on methanol

To study the features of the combustion process in a 2CH 10.5/12.0 diesel engine when working on methanol with a portion of diesel fuel in accordance with the purpose, research objectives and methodology, tests were conducted at the nominal speed mode at a speed of n = 1800 min−1 and at the maximum torque mode at n = 1400 min−1. Indicator diagrams were taken at the optimal setting of the fuel injection angle, with a constant cyclic supply of diesel fuel and a cyclic supply of methanol, which ensures that the value of the average effective pressure is maintained at the level at which the experimental diesel was shown. Based on the results of processing indicator diagrams, heat release graphs were constructed, the analysis of which is presented in this article.

КИНЕМАТИЧЕСКИЙ АНАЛИЗ УЗЛА ПРОМЕЖУТОЧНЫХ ШЕСТЕРЕН ТОПЛИВНЫХ НАСОСОВ РАСПРЕДЕЛИТЕЛЬНОГО ТИПА

In order to study the significance of the impact of wear on the working surfaces of parts of the intermediate gear assembly on the amount of plunger dead stroke and, therefore, on the cycle feed and advance fuel injection angle, we analyzed the critical positions of the parts of the assembly without the repair of its geometric parameters. In the process, the working surfaces of parts and mates are subject to intensive wear, which leads to an increase in the radial play of the intermediate gear. With the help of the developed device, the intermediate gears of the first and second pump sections of 70 ND-22/6 pumps from among the repair stock were examined at the specialized workshop of OAO “Yantikovskoe RTP”. From an analysis of the results of statistical processing of the backlash values in the nodes under study, it follows that in 75% of pumps the value of the radial play of the intermediate gear exceeds the allowable value for the first pumping section and 72% of the pumps for the second section. The paper proposes a method for determining the radial play of the intermediate gear drive of the plunger rotation drive of the distribution type pump. The design of the device for the in-place determination of the radial play of parts in the nodes of intermediate gears is given. Statistical indicators of the radial play of the intermediate gears of the plunger rotation mechanism were obtained. The percentage of shelf life of distribution type pumps is determined by the parameters of the technical condition of the intermediate gear assemblies. According to the research results, it was proposed to transfer the intermediate gear assemblies of the ND-22/6 pumps to the category of repair kits with their obligatory replacement when replacing pump sections.

Experimental research on the effect of reflected shock waves on the evolution of a high-pressure diesel spray

The shock wave has become a common phenomenon in modern diesel engines with the continuous increase in the fuel injection pressure. The shock wave reflects in the cylinder and affects the macroscopic structure of the spray and the mixing effect between the spray and surrounding air. In this study, the effects of the reflected shock wave on the evolution characteristics and the mixing characteristics of a high-pressure diesel spray were investigated using the Schlieren imaging method. The results show that the reflected shock wave significantly suppresses the development of the spray in the radial direction. However, the reflected shock wave has little effect on the development of the spray tip penetration. The volume and the average equivalence ratio of the spray under the reflected shock wave are also lower than those without the reflected shock wave. In addition, the evolution of the spray under different fuel injection angles was also analyzed. The results show that the different fuel injection angle affects the development of the spray width in the radial direction, which in turn has a significant influence on the spray cone angle.

Numerical Analysis of the Compression Ratio’s Influence, the Nature of the Fuel and the Injection Feed on the Cylinder Pressure

This article analyses numerically the simultaneous influence of the compression rate, fuel nature and the advanced injection of fuel on maximum cylinder pressure during the combustion phrase with the help of the Python Spyder calculation code. Indeed, several authors have shown that the combustion of biofuels which make it possible to compensate for fossil and exhaustible resources, presents a cylinder pressure higher by about 3.5% compared to that of conventional diesel D100. This increase in pressure can be reduced by the means of controlling parameters making it possible to preserve the life of the engine and also reduce nitrogen oxides (NOx) and particular matter (PM). This article has two objectives which are: putting in place a numerical tool for the evaluation and simulation of thermal engines and the influence of control parameters on cylinder pressure. The single zone 0D combustion model which considers only the physical phenomena and considers the mixed fuel as a perfect gas is used. The fuel used is the Neem biofuel produced by Doctor Merlin Ayissi of the University of Douala and the D100 diesel fuel. The results are obtained from three fuel injection angles of 20°, 13° and 10° before the TDC (Top Dead Centre) and three values of the engine compression rates of 15, 20 and 25. The delay in combustion is characteristic of the fuel used as illustrated by the cetane number. The results show that the cylinder pressure increases with increasing compression rate and a very high advanced injection. It also shows that the pressure is high when diesel D100 is used instead of D100 biodiesel.

Reacting flow analysis of a cavity-based scramjet combustor using a Jacobian-free Newton–Krylov method

ABSTRACTThe scramjet is a rather a new technology and there are many issues related to their operation, especially when it comes to the combustion processes. Combustion in high-speed flows causes various problems such as flame instability and poor fuel–air mixing efficiency. One of the methods used to overcome these problems is to recess a cavity in the combustor wall where a secondary flow is generated. In this study, a computational fluid dynamics (CFD) code is developed to analyse the reacting flow passing through the cavity-based scramjet combustor. The developed code is based on three-dimensional coupled Navier–Stokes and finite rate chemistry equations. An ethylene-air reduced chemical reaction model is used as a fuel–air combination. The Spalart–Allmaras model is utilised for turbulence closure. The non-dimensional form of the flow and chemical reaction equations are discretised using a finite volume method. The Jacobian-Free Newton–Krylov (JFNK) method is used to solve the coupled system of non-linear equations. The JFNK is a matrix-free solution method which improves the computational cost of Newton’s method. The parameters that affect the performance of the JFNK method are studied in the analysis of a scramjet combustor. The influence of the forcing term on the convergence of the JFNK method is studied in the analysis of scramjet combustor. Different upwind flux vector splitting methods are utilised. Various flux limiter techniques are employed for the calculations of higher order flux vectors. The effects of flux vector splitting and flux limiter methods on the convergence and accuracy of the JFNK method are evaluated. Moreover, the variations of the mixing efficiency with fuel injection angles are studied.

The Characteristic of Flow Field and Emissions of a Concentric Staged Lean Direct Injection (LDI) Combustor

The characteristic of flow field and emissions was investigated by numerical simulation for a concentric staged lean direct injection combustor, the non-reaction and reaction flow fields were studied under idle and takeoff conditions, and the effect of combustion heat release on flow field was analyzed, then the influence of injection angle on emissions were obtained. The investigation results indicated that the steady central recirculation zone could be formed under non-reaction and reaction conditions by medium swirl strength which the swirl angle is 32°, however, the size and reverse mass flow at reaction conditions is significantly increased than non-reaction conditions; the combustion reaction zone moves toward the outlet as the decrease of fuel injection angle, which reduce the resistant time of hot gas in combustor, and then the production of nitrogen oxides would be decreased.

Towards the development of an efficient low-NOx ammonia combustor for a micro gas turbine

Recent studies have demonstrated stable generation of power from pure ammonia combustion in a micro gas turbine (MGT) with a high combustion efficiency, thus overcoming some of the challenges that discouraged such applications of ammonia in the past. However, achievement of low NOx emission from ammonia combustors remains an important challenge. In this study, combustion techniques and combustor design for efficient combustion and low NOx emission from an ammonia MGT swirl combustor are proposed. The effects of fuel injection angle, combustor inlet temperature, equivalence ratio, and ambient pressure on flame stabilization and emissions were investigated in a laboratory high pressure combustion chamber. An FTIR gas analyser was employed in analysing the exhaust gases. Numerical modeling using OpenFOAM was done to better understand the dependence of NO emissions on the equivalence ratio. The result show that inclined fuel injection as opposed to vertical injection along the combustor central axis resulted to improved flame stability, and lower NH3 and NOx emissions. Numerical and experimental results showed that a control of the equivalence ratio upstream of the combustor is critical for low NOx emission in a rich-lean ammonia combustor. NO emission had a minimum value at an upstream equivalence ratio of 1.10 in the experiments. Furthermore, NO emission was found to decrease with ambient pressure, especially for premixed combustion. For the rich-lean combustion strategy employed in this study, lower NOx emission was recorded in premixed combustion than in non-premixed combustion indicating the importance of mixture uniformity for low NOx emission from ammonia combustion. A prototype liner developed to enhance the control and uniformity of the equivalence ratio upstream of the combustor further improved ammonia combustion. With the proposed liner design, NOx emission of 42 ppmv and ammonia combustion efficiency of 99.5% were achieved at 0.3 MPa for fuel input power of 31.44 kW.

Impact of Various Factors on the Performance and Emissions of Diesel Engine Fueled by Kerosene and Its Blend with Diesel

As a response to the single fuel concept introduced by the North Atlantic Treaty Organization (NATO) as well as increasing cases of adulteration of diesel fuel with kerosene, it is important for us to have a better understanding on the performance of diesel engine fueled by kerosene and its blend with diesel. An extensive numerical investigation on the combustion and emission formation of a diesel engine fueled by kerosene and its blend with diesel is presented in this paper. The impact of various factors such as the fuel blend ratio and the fuel injection angle on the performance of the engine was examined. The results indicated that the fuel with a higher percentage of kerosene tend to give higher maximum power output, lower carbon monoxide emission. It is also found that for each fuel, there is an optimum fuel injection angle that gives the highest maximum power output and relatively low emissions.

Numerical Investigation of Various Fuel Injection Angles on Interaction in Cold Kerosene-fueled Supersonic Flow

The incident shock wave strongly affects the transversal injection field in cold kerosene-fueled supersonic flow, possibly due to its affecting the interaction between incoming flow and the fuel through various operation conditions. Optimum selection of fuel injection parameters indicates optimum interaction between incoming flow and fuel. Based on three dimensional Couple Level Set & Volume of Fluids (CLSVOF) approach, a detailed Computational Fluid Dynamics model of a cold kerosene-fueled scramjet combustor is developed in this study. Next, the effects of various injection angles on the interaction between incident shock wave and transversal cavity injection are addressed. The injection angles are specified from 45̊ to 135̊ in 45̊increments when other operation parameters, i.e. the injection diameter, velocity and pressure drop are all constant. The CLSVOF-based predictions are focused on penetration height, span-wise expansion area, angle of shock wave and sauter mean diameter (SMD) distribution of the kerosene droplets. Our findings show that the penetration depth, span-wise angle and expansion area of the transverse cavity jet all increased with the injection angle, and that the kerosene droplets are more prone to breakup and atomization at the outlet of the combustor for the injection angle of 45̊. This study demonstrates the effectiveness of CLSVOF modeling for better understanding of kerosene-fueled supersonic mixing and scramjet combustor design improvement.

Diffusion MILD Combustion of Firing Pulverized-coal at a Pilot Furnace

This paper presents the computational investigation of the diffusion MILD (Moderate or Intense Low-oxygen Dilution) combustion of firing pulverized-coal at a pilot furnace. Dependences of the combustion performance are examined on the injection parameters, e.g., the fuel injection angle and the separation between the primary and secondary nozzles. Calculations are performed to examine the combustion characteristics, e.g., velocity and temperature distributions, CO and NO emissions, and char burnout. The validation of the modeling is carried out using the experimental measurements of Weber et al. (Proc. Combust. Inst. 30, 30 (2), 2623–2629 2005). Results reveal that an increase in the fuel injection angle or the separation reduces the peak temperature in the confluence region of the primary and secondary streams and thus the exhaust NO emission. During the coal MILD combustion, the (destroying) NO reburning mechanism is strongly involved so that the NO emission is below the NO production from the fuel-NO route, given that other routes of NO formation are unimportant. It is also found that the gasification reactions of char with CO2 and H 2O in coal MILD combustion appear to compensate for depression of the low O2 concentration on the coal burnout. In addition, several suggestions are made that could be useful for design of coal MILD burners.

PFI Dual Injection 엔진의 연료 분사각도와 분무각에 따른 엔진 내부 유동 및 연료 거동 특성

PFI Dual Injection 엔진의 연료 분사각도와 분무각에 따른 엔진 내부 유동 및 연료 거동 특성

Investigating the supersonic combustion efficiency for the jet-in-cross-flow

The purpose of this paper is to investigate the effect of impinging oblique shock on combustion efficiency of hydrogen injection into the supersonic cross-flow. The two-dimensional finite volume solver is developed to simulate the reacting flow, and the one-equation Spalart-Allmaras turbulence model is implemented to capture the turbulent flow characteristics. The impinging oblique shock is produced by a wedge that is located in the upper boundary of the flow field. Finding the best effective parameters on the combustion efficiency may lead to optimize the supersonic combustion chambers, from technological viewpoints. The variation of combustion efficiency versus various induced shock's collision positions with bottom wall in related to the fuel injection location is presented. In addition, the effect of induced shock strength on combustion process is investigated by changing the wedge's angle. Augmentation an additive, H2O2, to the fuel is the other parameter whose effect on combustion characteristics is studied in the disturbed field by impinging oblique shock. Finally, the effects of fuel injection angle as a predominant factor in flow and combustion features is illustrated in this paper. The results show that the shock impinging upstream of the injection slot, tilting the fuel jet to the upstream, increasing the oblique shock strength, and using hydrogen peroxide in fuel stream can effectively increase the combustion efficiency.